import java.lang.Math;
class Point{
	double x;
	double y;
	public Point(double x,double y) {
		this.x=x;
		this.y=y;
	}
}
public class Main extends Point{
	double r;
	public Main  (double x,double y,double r) {
		super(x,y);
		this.r=r;
	}
	public double area()
	{
		return Math.PI*r*r;
	}
	public static double area(double r)
	{	
		return Math.PI*r*r;
	}

	public static double area(Main  c)
	{
		
		return Math.PI*c.r*c.r;
	}
	public static void main(String[] args) {
		Main  circle=new Main (1,2,3);
		Main  b=new Main (3,4,5);
		System.out.println((float)circle.area());
		System.out.println((float)area(3));
		System.out.println("圆心为（3,4）半径为：5的圆的面积为：");
		System.out.println((float)area(b));
	}
}